Screw-propeller.



Patented Mar. 23, 1915.

M: iii/IIIIIII FFTFFL HERSEY STAPLES, 01E DIAMOND BLUFF, WISCONSIN.

SCREW-PROPELLER answer.

Specification of Letters Patent.

Patented Mar. 23, T915.

Application filed November 29, 1913. Serial 'No. 803,778.

1 of which the following is a specification.

This invention relates to improvements in the construction of screwpropellers, the present invention being an improvement upon theconstruction of screw propeller disclosed in my prior application filedJuly 8, 1913, Serial No. 777,887.

The object of the present invention 1s to provide a novel constructionof sectional hub and propeller fiukes or blades, whereby blades ofdifierent pitch or speed ratios may be employed, and a new fluke orblade readily substituted in place of a broken one, and particularly toa novel construction of parts whereby the blades are firmly and securelyclamped between the hub sections against liability of displacement.

The invention consists of the features of construction, combination andarrangement of parts hereinafter fully described and claimed, referencebeing had to the accompanying drawing in which Figure 1 is a plan viewof a propeller embodying my invention. Fig. 2 is a vertlcal longitudinalsection on the line 2-2 of Fig. 1. Fig. 3 is a vertical transversesection on the line 33 of Fig. 1. Fig. 4 is a transverse section on theline H of Fig. 1. Figs. 5 and 6 are perspective views of disassociatedhub sections. Fig. 7 is a perspective view of one of the flukes orblades.

Referring to the drawing, 1 designates the propeller shaft, 2 the hub,and-3 the removable flukes or blades. In the present instance T haveshown the use of a hub divided to provide a pair of cooperating bladeclamping sections, and'three equidistantly arranged flukes or blades,but it will of course be understood that a greater or lesser number ofblades may be employed and the hub sections correspondingly modified.

The hub 2 consists of a pair of transversely divided sections 4 and 5,secured from rotary motion on a tapered portion of the shaft by a key 6and from relative separation or endwise motion on the tapered portion ofthe shaft by clamping nuts 7 and 8 engaging threaded surfaces 9 and 10of the shaft, the construction being such that the hub sections arefirmly, yet detachably, fixed to the shaft. As shown, the hub sections 1and 5 are divided on an irregular transverse line, the meeting facesthereof presenting opposed longitudinal abutment surfaces 11andtransverse clamping surfaces 12, intersecting said abutment surfaces,between the opposed clamping surfaces of which hub sections the tangs 13of the blades are clamped. In accordance with my invention, the tangs 13of the blades are made somewhat spoon-shaped, or of concavo-convex form,and therespective pairs of coacting clamping surfaces 12 of the hubsections are properly shaped to receive and engage said tangs, one ofsaidsurfaces having a concaved contour, as shown at 14, the other asimilar convex contour, as shown at 15, the construction being such thatthe tangs of the blades will be interlocked with the clamping surfaces,and thereby held securely against possibility of movement in anydirection, it will be observed that this mode of connection insures thefirm retention as well as the bracing of the tangs,'to

adapt them to firmly withstand the pressures to which the blades aresubjected.

As shown, the hub sections are provided I with openings 16 for passageof the key 6,

and the tangs 13 of one of the blades 3 is I provided with a notch orrecess 17 to interlock with the key at the point where it crosses thesame. To further insure the retention of the blades against anypossibility of outward movement, the tangs 13 are-provided with enlargedthickened ends 18 to interlock with recesses 19 formed at the inner endsof the points of intersection of the faces 11 and 12.

It will be obvious that the construction of hub described enablesremovable blades having different working or speed ratios to beinterchangeably used and a broken blade to be readily removed andreplaced, without disturbing any of the other blades, and the advantagesof which will be apparent. The invention may also be employed in theconstruction of all kinds of blades propellers, fans or blowers.

I claim o A propeller comprising a shaft, a hub composed of sectionsdivided to present longitudinal abutment surfaces substantially parallelwith the axis of the propeller I to the axis of the propeller, said hubsections having lateral recesses communicating with ing said hubsections to the shaft and holdthe spaces between the inner ends of saiding the same assembled, 10 surfaces and extending inwardly beyond Intestimony whereof I aflix my signature the plane of the abutmentsurfaces, blades in presence of two witnesses.

having angularly disposed tangs disposed HERSEY STAPLES.

between said abutment and clamping sur- Witnesses: faces and portions toengageand interlock MARY L. NELSON,

with said lateral recesses, and means for fix- RALPH MCKEEN.

